The present invention relates to a display device for a vehicle that displays various information of the vehicle.
In vehicles, vehicle information such as a traveling speed, warning or the like of a vehicle are displayed on a display device on the vehicle. In such display devices for the vehicle, some of the display devices are a center meter type display device. In such display device, the display can be visually observed by a passenger in addition to a driver sitting on a driving seat of the vehicle. However, vehicle information is mainly necessary for a driver of a vehicle when the driver drives the vehicle. Therefore, the display devices for a vehicle are usually arranged in respective front portions of driving seats. A display of a display device for a vehicle arranged in a front portion of a driving seat is to be visually observed by a driver through a space inside of a steering wheel in a radial direction of the steering wheel.
Meanwhile, a number of kinds or an amount of content of vehicle information which can be grasped in a vehicle has been increased year by year. In the increased information, some of the information contents are not displayed in detailed by only a conventional display unit having an instrument or a symbol. For this reason, an auxiliary displaying is sometimes performed by using a variable display unit such as, for example, a liquid display device in addition to a displaying by using the conventional display unit. In this case, the variable display unit is arranged in a front portion of a driving seat together with the conventional display unit (e.g., patent documents 1 and 2).
However, a portion where a driver can visually observe through a space inside of a steering wheel in the radial direction thereof, is limited and a size of the variable display unit to be arranged is also limited. Therefore, in order to eliminate the limitation of the size of the variable display unit, it is necessary to perform the auxiliary displaying by using a display unit which is placed at a position where a driver can visually observe through a space outside of the steering wheel in the radial direction thereof (e.g., patent documents 3 and 4).    Patent Document 1: JP-A-2002-356118    Patent Document 2: JP-A-2006-131103    Patent Document 3: JP-A-9-196690    Patent Document 2: JP-A-2008-1120
In the above described patent documents 3 and 4, the variable display unit and the conventional display unit are arranged such that a driver can visually observe both of the display units through a space above the steering wheel. However, it is preferable to attain a field of view above the steering wheel for visibility in the forward direction of the vehicle. Therefore, it is ideal that the conventional display unit and the variable display unit are separately arranged so as not to obstruct the field of view in the forward direction of the vehicle.
However, the separately arrangement as described in the above gives a visual impression that both of the display units are independent different things. Accordingly, even when vehicle information having a correlation with vehicle information displayed on the conventional display unit, is displayed on the variable display unit, there is a possibility for the driver to overlook the vehicle information.
The above problem may commonly occur in cases where contents having correlated vehicle information are displayed on a plurality of display units irrespective of kinds of the display units and what kind of display style each of the display units uses.